The PEPC Spreader Bar Assembly consists of a spreader bar that will be attached to the PEPC Cell Housing or the Midplane Transportation Fixture during operation. While in use in the OAB (Optics Assembly Building), the Spreader Bar Assembly will be manipulated by the NOID (New Optics Insertion Device). The other critical components of the assembly are the three angular contact bearing swivels that attach the spreader bar to the lifting mechanism and the corner clamps which are used to capture the Cell Housing.

The Scaled Thermal Explosion Experiment (STEX) has been developed to quantify the violence of thermal explosion under well defined and carefully controlled initial and boundary conditions. Here we present results with HMX-based explosives (LX-04 and PBX-9501) and with Composition B. Samples are 2 inches (50 mm) in diameter and 8 inches (200 mm) in length, under confinement of 7,500-30,000 psi (50-200 MPa), with heating rates of 1-3 C/hr. We quantify reaction violence by measuring the wall velocity in the ensuing thermal explosion, and relate the measured velocity to that expected from a detonation. Results with HMX-based explosives (LX-04 and PBX-9501) have shown the importance of confinement and HMX solid phase, with reaction violence ranging from mild pressure bursts to near detonations. By contrast, Composition B has shown very violent reactions over a wide range of conditions.

We developed a reduced description of kinetic effects that is included in a fluid model of stimulated Brillouin backscattering (SBS) in low Z plasmas (e.g. He, Be). Following hybrid-PIC simulations, the modified ion distribution function is parametrized by the width {delta} of the plateau created by trapping around the phase velocity of the SBS-driven acoustic wave. An evolution equation is derived for {delta}, which affects SBS through a frequency shift and a reduced Landau damping. This model recovers the linear Landau damping value for small waves and the time-asymptotic nonlinear frequency shift calculated by Morales and O'Neil. Finally we compare our reduced model with Bzohar simulations of a Be plasma representative of experiments that have shown evidence of ion trapping.

Ignition hohlraum designs use low Z gas fill to slow down the inward progress of high Z ablated plasma from the hohlraum walls preventing large laser spot motion and capsule drive asymmetries. In order to optimize the ignition design, the gas hydro-coupling effect to a fusion capsule asymmetry is presently being assessed in experiments at the Omega laser facility with gas filled hohlraums and foam balls. Our experiments measure the effects of the pressure spike that is generated by direct gas heating by the drive laser beams on the capsule surrogate for various hohlraum gas fill densities (0-2.5 mg/cc). To isolate the effect of the gas-hydro coupling pressure, we have begun by using plastic ''hohlraums'' to reduce the x-ray ablation pressure. The foam ball images measured by x-ray backlighting show increasing pole-hot pressure asymmetry for increasing gas pressure. In addition, the gas hydrodynamics is studied by imaging of a low concentration Xe gas fill dopant. The gas fill self-emission. shows the early pressure spike and its propagation towards the foam ball, as well as the gas stagnation on the holraum axis at later times, both contributing to the capsule asymmetry. These first gas hydro-coupling results are compared to LASNEX simulations.

Sodium aluminum hydrides have gained attention due to their high hydrogen weight percent (5.5% ideal) compared to interstitial hydrides, and as a model for hydrides with even higher hydrogen weight fraction. The purpose of this paper is to investigate the Ti-compounds that are formed under solution-doping techniques, such as wet doping in solvents such as tetrahydrofuran (THF). Compound formation in Ti-doped sodium aluminum hydrides is investigated using x-ray diffraction (XRD) and magic angle spinning (MAS) nuclear magnetic resonance (NMR). We present lattice parameter measurements of crushed single crystals, which were exposed to Ti during growth. Rietveld refinements indicate no lattice parameter change and thus no solubility for Ti in NaAlH{sub 4} by this method of exposure. In addition, x-ray diffraction data indicate that no Ti substitutes in NaH, the final decomposition product for the alanate. Reaction products of completely reacted (33.3 at. %-doped) samples that were solvent-mixed or mechanically milled are investigated. Formation of TiAl{sub 3} is observed in mechanically milled materials, but not solution mixed samples, where bonding to THF likely stabilizes Ti-based nano-clusters. The Ti in these clusters is activated by mechanical milling.

The transmission characteristics of the optical fiber are of utmost importance for optical telecommunication systems. Indeed, the optical signal experiences all kinds of losses as it propagates and demands the use of regenerators or repeaters along the fiber link, [7]. Attenuation (loss) is a relationship between the optical output power and the optical input power in a fiber optic system. It is a measure of the decay of signal strength, or loss of light power, that occurs as light pulses propagate through the length of the fiber.

New amorphous-metal and ceramic coatings applied by the high-velocity oxy-fuel (HVOF) process may reduce the waste package materials cost of the Yucca Mountain high-level nuclear waste repository by over $4 billion (cost reduction of 27 to 42%). Two critical requirements that have been determined from design analysis are protection in brines that may evolve from the evaporative concentration of pore waters and protection for waste package welds, thereby preventing exposure to environments that might cause stress corrosion cracking (SCC). Our efforts are directed towards producing and evaluating these high-performance coatings for the development of lower cost waste packages, and will leverage a cost-effective collaboration with DARPA for applications involving marine corrosion.

We present the first measurements of the absolute albedos of hohlraums made from gold or from high-Z mixtures. The measurements are performed over the range of radiation temperatures (70-100 eV) expected during the foot of an indirect-drive temporally-shaped ignition laser pulse, where accurate knowledge of the wall albedo (i.e. soft x-ray wall re-emission) is most critical for determining capsule radiation symmetry. We find that the gold albedo agrees well with calculations using the super transition array opacity model, potentially providing additional margin for ICF ignition.

We have developed a multiple monochromatic x-ray imaging diagnostic using an array of pinholes coupled to a multilayer Bragg mirror, and we have used this diagnostic to obtain unique multispectral imaging data of inertial-confinement fusion implosion plasmas. Argon dopants in the fuel allow emission images to be obtained in the Ar He-b and Ly-b spectral regions, and these images provide data on core temperature and density profiles. We have analyzed these data to obtain quasi-three-dimensional maps of electron temperature and scaled electron density within the core for several cases of drive symmetry, and we observed a two-lobed structure evolving for increasingly prolate-asymmetric drive. This structure is invisible in broad-band x-ray images. Future work will concentrate on hydrodynamics simulations for comparison with the data.

As public interest in phytonutrition continues to increase, the result will be an augmented demand for extensive phytochemical research. The fact that foods are inherently phytochemically complex dictates a need to apply scientific techniques, which can detect synergistic interaction among the many active principles and adjuvant substances in the plant, and furthermore, modify the activities of these components. As illustrated by the experiments discussed in this presentation, the advantages of AMS are unique and extensive. These advantages are best summarized by Dr. John Vogel, an originator of biological AMS experimentation: ''AMS brings (at least) three advantages to biochemical tracing: high sensitivity for finding low probability events or for use of physiologic-sized doses; small sample sizes for painless biopsies or highly specific biochemical separations; and reduction of overall radioisotope exposures, inventories, and waste streams.'' AMS opens the door to increased phytochemical tracing in humans to obtain biochemical data concerning human health at dietary relevant levels of exposure. AMS, thus, obviates the need for uncertain extrapolations from animal models, which express marginal relevance to human metabolism. The unparalleled capabilities and benefits of AMS will undoubtedly establish this particular MS technique as an important analytical tool in phytochemical research.

There is a great deal of information pertaining to wavelets readily available from various sources; several of the more recent sources describe the lifting technique for constructing wavelets. The tutorial paper by Sweldens and Schr{umlt o}der [1] gives a thorough explanation of the lifting approach for Haar bases. While it provides an excellent introduction to the topic, it is not immediately obvious how this approach is extended to nonuniformly spaced data on finite intervals. The present paper provides intermediate steps that supplement the material in [1]. After working through the following discussion, the reader should have no problem deriving the relevant equations presented in Sweldens and Schr{umlt o}der's article. Because of the abundance of information on the Haar basis, this discussion will instead work through the steps using a linear basis set.

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The 2003 RIA R&D Workshop was held on August 26-28, 2003 at the Four Points Sheraton Hotel in Bethesda, Maryland. This Workshop was chaired by Satoshi Ozaki of BNL and sponsored by the Nuclear Physics Division of DOE, with the help of Oak Ridge Institute for Science and Education (ORISE). The purpose of this workshop was to understand the present status of R&D efforts for RIA, to evaluate the needs for further R&D, and to identify opportunities for international collaborations. The workshop examined and documented the current pre-conceptual design for RIA, identifying areas where decisions on technical options remain. The status of the current RIA R&D program was documented, recognizing areas where efforts were needed in light of what had been learned. The ongoing and planned R&D activities for operating and planned rare-isotope facilities were presented, enabling the workshop to be a venue to develop coordinated R&D efforts of mutual benefit to U.S. and international efforts. The scientific program for the first day (August 26, 2003) consisted mostly of invited talks presented by major research groups involved in RIA and other RI beam facilities. The talks included those covering: Science of RIA and the RIA Facility Performance Requirements; The Reference …

Progress in the field of computational combustion over the past 50 years is reviewed. Particular attention is given to those classes of models that are common to most system modeling efforts, including fluid dynamics, chemical kinetics, liquid sprays, and turbulent flame models. The developments in combustion modeling are placed into the time-dependent context of the accompanying exponential growth in computer capabilities and Moore's Law. Superimposed on this steady growth, the occasional sudden advances in modeling capabilities are identified and their impacts are discussed. Integration of submodels into system models for spark ignition, diesel and homogeneous charge, compression ignition engines, surface and catalytic combustion, pulse combustion, and detonations are described. Finally, the current state of combustion modeling is illustrated by descriptions of a very large jet lifted 3D turbulent hydrogen flame with direct numerical simulation and 3D large eddy simulations of practical gas burner combustion devices.

Detailed reactor physics and safety analyses have been performed for the 20 MW D{sub 2}O moderated research reactor (NBSR) at the National Institute of Standards and Technology (NIST). The analyses provide an update to the Final Safety Analysis Report (FSAR) and employ state-of-the-art calculational methods. Three-dimensional MCNP Monte Carlo neutron and photon transport calculations were performed to determine the safety parameters for the NBSR. The core depletion and determination of the fuel compositions were performed with MONTEBURNS. MCNP calculations were performed to determine the beginning, middle, and end-of-cycle power distributions, moderator temperature coefficient, and shim arm, beam tube and void reactivity worths. The calculational model included a plate-by-plate description of each fuel assembly, axial mid-plane water gap, beam tubes and the tubular geometry of the shim arms. The time-dependent analysis of the primary loop was determined with a RELAP5 transient analysis model including the pump, heat exchanger, fuel element geometry, and flow channels for both the six inner and twenty-four outer fuel elements. The statistical analysis used to assure protection from critical heat flux (CHF) was performed using a Monte Carlo simulation of the uncertainties contributing to the CHF calculation. The power distributions used to determine the local fuel conditions …

The Immobilized Low Activity Waste (ILAW) generated from the Hanford Site will be disposed of in a vitrified form. It is expected that leachate from the vitrified waste will have a high pH and high ionic strength. The objective of this study was to determine the influence of glass leachate on the hydraulic, physical, mineralogical, and sorptive properties of Hanford sediments. Our approach was to put solutions of NaOH, a simplified surrogate for glass leachate, in contact with quartz sand, a simplified surrogate for the Hanford subsurface sediment, and Warden soil, an actual Hanford sediment. Following contact with three different concentrations of sodium hydroxide solutions, changes in hydraulic conductivity, porosity, moisture retention, mineralogy, aqueous chemistry, and soil-radionuclide distribution coefficients were determined. Under chemical conditions approaching the most caustic glass leachate conditions predicted in the near-field of the ILAW disposal site, approximated by 0.3 M NaOH, significant changes in mineralogy were observed. The clay minerals of the Hanford sediment evidenced the greatest dissolution thereby increasing the relative proportions of the more resistant minerals, e.g., quartz, feldspar, and calcite, in the remaining mass. Some re-precipitation of solids (mostly amorphous gels) was observed after caustic contact with both solids; these precipitates increased the …

An algorithm for determining the position of the KDP back-reflection image was developed. It was compared to a centroid-based algorithm. While the algorithm based on centroiding exhibited a radial standard deviation of 9 pixels, the newly proposed algorithm based on classical matched filtering (CMF) and a Gaussian fit to correlation peak provided a radial standard deviation of less than 1 pixel. The speed of the peak detection was improved from an average of 5.5 seconds for Gaussian fit to 0.022 seconds by using a polynomial fit. The performance was enhanced even further by utilizing a composite amplitude modulated phase only filter; producing a radial standard deviation of 0.27 pixels. The proposed technique was evaluated on 900+ images with varying degrees of noise and image amplitude as well as real National Ignition Facility (NIF) images.

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High energy density experiments, such as those planned at the National Ignition Facility (NIF), use mesoscale targets with the goals of studying high energy density physics, inertial confinement fusion, and the support of national security needs. Mesoscale targets are typically several millimeters in size and have complex micrometer-sized structures composed of high-density metals and low-density foams and ices. These targets are designed with exacting tolerances that are difficult to achieve at present. Deviation from these tolerances can result in compromise of experimental goals and thus it is necessary to determine as-built properties of these targets using NDE techniques. Radiography and computed tomography are being used to investigate these targets, but the mix between phase and absorption information is difficult to separate, making interpretation of results difficult. We have recently improved the HADES radiographic simulation code to include phase in simulations, as an aid for doing NDE on mesoscale targets. In this paper we report on how we extended HADES to incorporate phase effects, and compare simulations with a variety of experimental test results.

Newsletter of the Texas Department of Health discussing the news, activities, and events of the organization and other information related to health in Texas.

The United States Arctic Research Commission's statement on the importance of icebreakers and the vital role that they play in the United States' strategic presence in the polar regions.

Continuum mechanics relies on the fundamental notion of a mesoscopic volume"element" in which properties averaged over discrete particles obey deterministic relationships. Recent work on granular materials suggests a continuum law may be inapplicable, revealing inhomogeneities at the particle level, such as force chains and slow cage breaking. Here, we analyze large-scale three-dimensional Discrete-Element Method (DEM) simulations of different granular flows and show that an approximate"granular element" defined at the scale of observed dynamical correlations (roughly three to five particle diameters) has a reasonable continuum interpretation. By viewing all the simulations as an ensemble of granular elements which deform and move with the flow, we can track material evolution at a local level. Our results confirm some of the hypotheses of classical plasticity theory while contradicting others and suggest a subtle physical picture of granular failure, combining liquid-like dependence on deformation rate and solid-like dependence on strain. Our computational methods and results can be used to guide the development of more realistic continuum models, based on observed local relationships betweenaverage variables.